<template>

  <div class="app-container">

    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="提交审核"/>
    </el-steps>

    <el-form label-width="120px">
        <el-form-item label="课程标题">
            <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
        </el-form-item>

    <!-- 所属分类：级联下拉列表 -->
    <!-- 一级分类 -->
    <el-form-item label="课程类别">
      <el-select
        v-model="courseInfo.subjectParentId"
        placeholder="一级分类"
         @change="updateSubSubject">
        <el-option
          v-for="subject in subjectNestedList"
          :key="subject.id"
          :label="subject.label"
          :value="subject.id"/>
      </el-select>
      <!-- 二级分类 -->
      <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
        <el-option
          v-for="subject in subSubjectList"
          :key="subject.id"
          :label="subject.label"
          :value="subject.id"/>
      </el-select>
    </el-form-item>



    <!-- 课程讲师 -->
    <el-form-item label="课程讲师">
      <el-select
        v-model="courseInfo.teacherId"
        placeholder="请选择">
        <el-option
          v-for="teacher in teacherList"
          :key="teacher.id"
          :label="teacher.name"
          :value="teacher.id"/>
      </el-select>
    </el-form-item>

        <el-form-item label="总课时">
            <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
        </el-form-item>

        <!-- 课程简介 TODO -->
        <!-- 课程简介-->
        <el-form-item label="课程简介">
            <tinymce :height="300" v-model="courseInfo.description"/>
        </el-form-item>

        <!-- 课程封面-->
        <el-form-item label="课程封面">

          <el-upload
            :show-file-list="false"
            :on-success="handleAvatarSuccess"
            :before-upload="beforeAvatarUpload"
            :action="BASE_API+'/eduoss/file/upload'"
            class="avatar-uploader">
            <img :src="courseInfo.cover">
          </el-upload>
        </el-form-item>


        <el-form-item label="课程价格">
            <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
        </el-form-item>

        <el-form-item>
            <el-button :disabled="saveBtnDisabled" type="primary" @click="next">保存并下一步</el-button>
        </el-form-item>
    </el-form>
  </div>
</template>
<script>
import courseApi from '@/api/edu/course'
import teacherApi from '@/api/edu/teacher'
import subjectApi from '@/api/edu/subject'
import Tinymce from '@/components/Tinymce'
export default {
  components: { Tinymce },
  data() {
    return {
        BASE_API: process.env.BASE_API, // 接口API地址
        OSS_PATH: process.env.OSS_PATH, // 对象存储的地址
        saveBtnDisabled: false, // 保存按钮是否禁用,默认不禁用
        courseInfo:{}, // 保存课程信息的对象
        teacherList:[],
        subjectNestedList:[],
        subSubjectList:[],
    }
  },

  watch: {
    $route(to, from) {
      console.log('watch $route')
      this.init()
    }
  },

  created() {
    console.log('info created')
    this.getTeacherList()
    this.getSubjectTree()
    this.init()
    this.courseInfo.cover = this.OSS_PATH + '/cover.png'
  },

  methods: {
      init() {
          if (this.$route.params && this.$route.params.id) {
              this.courseInfo.id = this.$route.params.id
              courseApi.getCourse(this.courseInfo.id)
                .then(response => {
                  this.courseInfo = response.data.data
                  this.updateSubSubject(this.courseInfo.subjectParentId)
                })
        } else {
            this.courseInfo = {}
        }
      },
    next() {
        if (!this.courseInfo.id) {
            this.saveCourseInfo()
        } else {
            this.updateCourseInfo()
        }
    },

    getTeacherList() {
      teacherApi.getAllTeachers()
        .then(response => this.teacherList = response.data.data)
    },

    getSubjectTree() {
      subjectApi.getSubjectsInTree()
        .then(response => this.subjectNestedList = response.data.data)
    },
    updateSubSubject(id) {
      for(var i = 0; i < this.subjectNestedList.length; i++) {
        if (this.subjectNestedList[i].id === id) {
          this.subSubjectList = this.subjectNestedList[i].children
          // this.courseInfo.subjectId = ''
          return;
        }
      }
    },
    beforeAvatarUpload(file){
      const isJPG = (file.type === 'image/jpeg' || file.type === 'image/png')
      const isLt1M = file.size / 1024 / 1024 < 1
      if (!isJPG) {
        this.$message.error('上传头像图片只能是 JPG或PNG 格式!')
      }
      if (!isLt1M) {
        this.$message.error('上传头像图片大小不能超过 1MB!')
      }
      return isJPG && isLt1M
    },

    handleAvatarSuccess(res, file){
      // console.log(res)// 上传响应
      // console.log(URL.createObjectURL(file.raw))// base64编码
      this.courseInfo.cover = res.data.url  // 保存地址，留给数据库，顺便更新显示
      console.log(this.courseInfo.cover)
    },

    saveCourseInfo() {
        this.saveBtnDisabled=true // 禁用
        courseApi.addCourse(this.courseInfo)
            .then(response => {
              if (response.success === true) {
                this.$message({
                    type: 'success',
                    message: '保存成功!'
                });
                this.$router.push({ path: '/course/chapter/' + response.data.id })
              } else {
                this.$message({
                    type: 'error',
                    message: '保存失败!'
                });
                this.saveBtnDisabled=false // 不禁用
              }
            })
            .catch(error => {
                this.$message({
                    type: 'error',
                    message: '保存失败!'
                });
                this.saveBtnDisabled=false // 不禁用
            })
    },
    updateCourseInfo() {
        this.saveBtnDisabled=true // 禁用
        courseApi.updateCourse(this.courseInfo)
            .then(response => {
              if (response.success === true) {
                this.$message({
                    type: 'success',
                    message: '保存成功!'
                });
                this.$router.push({ path: '/course/chapter/' + this.courseInfo.id })
              } else {
                this.$message({
                    type: 'error',
                    message: '保存失败!'
                });
                this.saveBtnDisabled=false // 不禁用
              }
            })
            .catch(error => {
                this.$message({
                    type: 'error',
                    message: '保存失败!'
                });
                this.saveBtnDisabled=false // 不禁用
            })
    }
  }
}
</script>

<style scoped>
.tinymce-container {
  line-height: 29px;
}
</style>